life Review In Vitro Measurements of Cellular Forces and their Importance in the Lung—From the Sub- to the Multicellular Scale Peter Kolb 1, Annika Schundner 2, Manfred Frick 2,* and Kay-E. Gottschalk 1,* 1 Institute of Experimental Physics, Ulm University, 89069 Ulm, Germany;
[email protected] 2 Institute of General Physiology, Ulm University, 89069 Ulm, Germany;
[email protected] * Correspondence:
[email protected] (M.F.);
[email protected] (K.-E.G.) Abstract: Throughout life, the body is subjected to various mechanical forces on the organ, tissue, and cellular level. Mechanical stimuli are essential for organ development and function. One organ whose function depends on the tightly connected interplay between mechanical cell properties, biochemical signaling, and external forces is the lung. However, altered mechanical properties or excessive mechanical forces can also drive the onset and progression of severe pulmonary diseases. Characterizing the mechanical properties and forces that affect cell and tissue function is therefore necessary for understanding physiological and pathophysiological mechanisms. In recent years, multiple methods have been developed for cellular force measurements at multiple length scales, from subcellular forces to measuring the collective behavior of heterogeneous cellular networks. In this short review, we give a brief overview of the mechanical forces at play on the cellular level in the lung. We then focus on the technological aspects of measuring cellular forces at many length scales. We describe tools with a subcellular resolution and elaborate measurement techniques for collective Citation: Kolb, P.; Schundner, A.; multicellular units. Many of the technologies described are by no means restricted to lung research Frick, M.; Gottschalk, K.-E In Vitro and have already been applied successfully to cells from various other tissues.